WaterGuru Sense S2 Smart Pool Monitor – Digital Pool & Spa Water Tester for Chlorine, pH, CYA & Alkalinity – Wi-Fi Enabled – Includes C5 Cassette, Float Ring & Batteries

Purchased my WaterGuru in 2024, and in December of 2025, it kept failing to measure. I contacted customer support and it turns out I had a bad motor on my unit. Joan was awesome and ended up sending me a new unit for no charge. I will admit, before the unit crapped out on me, WaterGuru has made it super easy to help maintain the proper chemicals in my pool year-round.

More failed readings that successes. Was really hoping this would make water testing easier, but it's the opposite for me. The app looks nice, easy to start a reading. But having to wait 10-12 minutes only for it to tell me it failed, then have to wait for 5-10 minutes for the "failed" message to go away is just a big waste of my time. I now have to go check the device, see if there's debris, see if it's in water, all of the troubleshooting steps. Everything is always fine, it just fails. So now I have to pull out my test kit and do it manually anyways. Way too much money to make my process even more frustrating. They also charge $15 shipping for the cassettes. So sorry i bought this.

I had the V1 of this and then later bought the V2 — and I love both. The updates are noticeable and it works even better this time around. Makes pool maintenance so much easier and less of a chore. Sturdy, reliable, and genuinely helpful to have around. Highly recommend if you want something that actually simplifies the job!

Pros: Testing seems to be pretty accurate. App is free and makes it convenient to monitor the pool conditions. The app gives suggestions and tips on improving various levels. Cons: Testing is done through cartridges. If you only test the water once per day, each cartridge will last about a month. A 5-pack of cartridges is $150... which is a little spendy. My biggest complaint is the battery life. The unit takes 4 C-cell batteries that only last about 2 weeks (based on Arizona heat in July-Aug). I would think a solar powered unit would be a better eco-friendly option.

I had been one of the earliest pHin users, until Hayward acquired it and then eventually shut it down. I can understand why, since I had received in total 5 warranty replacement units. Then, I decided to go without a monitoring device for one season, which worked fine, until it didn't this year, when I went on a two week international trip and then I returned to a full algae bloom. My gamble that I would be back in time did not pay off, so I got the WaterGuru2 to stop flying blind and Wow! it's so great to have this level of fine grained data. I had been toying with Pentair pH & CL test kits and then the Taylor test kit too, but now I always exactly where my measurements are at. Now I've got a much better handle on all the major variables in my pool, which actually took a while to fully understand since I didn't know any of this before. As you can see from my screen shots, my pH is currently a bit low, but I'm told that's reasonable since I use the Tri-Chlor slow dissolving tablets, but my CYA (CYanuric Acid) is through the roof too high. We figured out today that this is because I had been using 99% DiChlor to shock my pool, which spas like to use, but it's not appropriate for my pool, so I need to switch to 68% Calcium Hypo. I'm also going to see if a new CYA remover does what it says it can do, to get my CYA down to normal levels. I'm also going to add in Green to Clean since my high CYA is preventing the full killing of some nagging algae that still remains and likes to come back. The WaterGuru support team, both Tier 1 and Tier 2 have been a true pleasure to work with. With your purchase of the WaterGuru2, you get two types of Sense2 cartridges, 1 C5, which monitors pH, FC plus CYA, Hardness and total Alkalinity and lasts 30 days, and 2 C2's, which measures just pH and FC daily and these each last for 60 days. Once you get into a steady state C2's are enough. By the way, if you're recovering from something as bad as an algae bloom, please refrain from excessively invoking "Measure" on the WaterGuru2 app, since this will shorten the life of the cassette dramatically, since the measuring film scrolls through the cartridge and it will run out faster. By default the WaterGuru2 measures the water once a day and that's actually good enough for residential owners. Anyone who loves data and is tired of "winging it", or "excessively shocking your pool", or "just paying too much monthly to your pool person" should get a WaterGuru 2.